Problem B - Snow Clearing
-------------------------

As the days become shorter and the nights become longer we turn our
thoughts to snow clearing. Due to budget cuts, the Big Noisy City has
exactly one snow plow. The plow can clear exactly one lane of a road in
a single pass. Whenever there is snow on the ground, the plow departs
from its hangar and tours the city, plowing as it goes. What is the
minimum time that the plow needs to clear every lane of every road?

All roads are perfectly straight, with one lane in each direction. The
plow can turn any direction (including a U-turn) at any intersection,
and can turn around at the end of any street. The plow travels at 20
km/h if it is plowing, and 50 km/h if the lane it is driving on has
already been plowed. It is possible to reach all streets from the
hangar.

Input
-----

There will be multiple test cases. Each test case is structured as
follows: The first line of input contains three integers: the number n
of streets in the city (n <= 100), and the x,y coordinates of the hangar
(in metres). n lines follow. Each gives the coordinates (in metres) of
the beginning and end of a street.  

The last test case is followed by a line that cotains three zeros.
No output should be created for this last line.

Output
------

Your output should be the time, in hours and minutes, required to clear
the streets and return to the hangar. Round to the nearest minute.

Sample Input
------------

3 0 0
0 0 10000 10000
5000 -10000 5000 10000
5000 10000 10000 10000
0 0 0

Output for Sample Input
-----------------------

3:55